I'm not sure what my issue is. When I type in the URL to load the Dundas DB login screen Iframe it'll load just fine inside of our network. However, I went home to see if the URL still worked and it won't load the Iframe at all; it'll say "this ip address took too long to respond." I cannot provide the URL for privacy reasons however, I'll be happy to explain any of the configuration settings to see if I'm missing something?
It sounds like a networking issue on your end.
You should check with your IT department to see if there's anything in your company firewall which would prevent the Dundas server from being accessed from outside your internal network.